Many folks are less than happy about the way killer whales, including celebrity orca Shamu, are treated at SeaWorld in San Diego, California.

Now Jackass star Steve-O has admitted that he was responsible for changing a freeway sign leading to the theme park from Sea World Drive to Sea World SUCKS in May.

The 40-year-old revealed how he did it in a video posted to his YouTube page - and now he could face possible charges for defacing public property, according to TMZ.

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Mea culpa: Steve-O is reportedly under investigation by the California Highway Patrol after he admitted defacing a freeway sign in protest at the way SeaWorld keeps its killer whales

It's a fishy tale: The Jackass star posted a Youtube video on Wednesday showing he was the mystery vandal responsible for changing Sea World Drive to Sea World SUCKS in May

The video shows the prankster scaling a pole to a maintenance platform below the huge sign, 20ft or more above the ground, in broad daylight.

Then he covered the word Drive with the word SUCKS in white on green board to match the sign.

'I'm putting my foot down for Shamu,' the celebrity, whose real name is Steve
Glover, said in the clip. 'If doing that was wrong, I don't want to be right. Screw you SeaWorld!'

He posted the video on Wednesday along with two Instagram shots showing him committing the dastardly deed, including one or him hanging upside down, captioned: 'I filmed myself committing a crime in the middle of California's 5 Freeway.

Not so easy: The 40-year-old, pictured hanging upside down from the freeway sign as cars sped by in this Instagram snap, revealed it took him five tries to scale the pole up to the maintenance platform

Tough spot: The prankster wriggled out of this tricky situation as he continued his mission to get up to the sign

'It took me five tries to finish the job - here's one of them - the rest of the video is on http://youtube.com/steveo -- it might not last long on there, so hurry up and check it out now. #SeaWorldSucks #yeahdude #steveo

The video quickly caught the eye of Caltrans, the body responsible for highway maintenance, and officials there tipped off the California Highway Patrol, which is allegedly investigating Steve-O's actions.

TMZ's sources claimed it's likely the case will be referred to prosecutors and the celebrity will be charged.

Close to his goal: The celebrity was absolutely determined to accomplish his dastardly deed

However, Steve-O's protest might have had some effect.

Stung by criticism of its treatment of killer whales, SeaWorld said on August 15 that it would double the size of the environments for the orcas at its three theme parks and fund research on the animals plus programs to protect ocean health and whales in the wild.

Concerns about keeping large marine mammals in captivity were raised in the 2013 documentary Blackfish that suggested captivity and SeaWorld’s treatment provoked violent behavior in the creatures.

He's on top of it: Steve-O, aka Steve Glover, unrolled his replacement SUCKS sign on the maintenance platform before attaching it